RESULTS: The observed helmet rate across all study sites was 33% during nighttime and 48% during daytime, with proportions up to ten times higher among drivers compared with passengers. Self-reported helmet use was higher than observed use. Within the past 30 days, 60% of respondents reported that they "always" wore a helmet when they were drivers while only 24% reported they "always" wore a helmet as a passenger. Reported barriers for use among drivers included: "driving route", "forgetfulness", and "inconvenience/discomfort.